Laryngeal mask airway and uncuffed tracheal tubes are equally effective for low flow or closed system anaesthesia in children

Abstract

Low flow and closed system anaesthesia have considerable advantages in economy, limited atmospheric pollution, and maintenance of humidification and temperature. To benefit from these techniques leakage from the breathing system should be as low as possible. The sealing of the airway is crucial to ensure this. Therefore, we have investigated in 30 children, aged 2-6 yr, the effectiveness of the laryngeal mask airway (LMA) and the uncuffed tracheal tube (TT) for closed system paediatric anaesthesia, during positive pressure ventilation, in a prospective, randomized study. Ventilation was adequate in all cases with both devices. Loss of gas from the breathing system was less than 100 ml min-1 in 13 (87%) patients in the LMA and in 12 (80%) patients in the TT group, with a maximum of approximately 700 ml min-1 in the TT and approximately 350 ml min-1 in the LMA group. We conclude that the airway sealing with both devices was tight enough to perform low flow or closed system anaesthesia in paediatric patients aged 2-6 yr.